Il6 ECHINOIDEA. I. 



tooth; the outer corners of the basal part are strongly produced in a wing-shaped manner, and the 

 holes in the corners are most frequently somewhat lengthened. No neck or perhaps a short one; as 

 I have only had dried specimens for examination, I have not been able to decide this fact with cer- 

 tainty; the stalk compact. In the tridentate pedicellariae (PI. XIX. Fig. 39) the blade is rather broad 

 with a strong, somewhat thorny net of meshes at the bottom. The edge is strongly indented, espe- 

 cially in the outer half, where the valves join; in the lower half they are apart, but not very much. 

 The ophicephalous pedicellarise have an almost straight edge, which is otherwise finely serrate as 

 usual; the teeth, as is often the case, continue down the upper ends of the apophysis. The triphyllous 

 pedicellarise (PI. XIX. Fig. 29) are very peculiar, the upper end of the apophysis forming a cover-plate, 

 from which digitate projections pass over the blade, which is curved strongly inward in the middle. 

 The edge smooth as usual. The spicules are bihamate, very few in number. 



Evechimis rariluberculatus Bell is by Farquhar (145) taken to be young specimens of E.chlo- 

 roticus. It is certain that it is very similar to chloroticus, but I cannot regard it as proved that it is 

 synonymous with this species, as the tridentate pedicellarise (PL XIX. Fig. 7) show a considerable dif- 

 ference from those of chloroticus. They have no coarse indentations in the edge, which is almost 

 straight and very slightly serrate, only at the lowermost part there are a few larger indentations; the 

 net of meshes in the bottom is slight, not thorny. The valves join through almost their whole 

 length. Perhaps similar pedicellariae may be found in chloroticus together with the form described 

 above; in my specimens, however, I have not been able to find such. For the present I must then 

 regard rarituberculatus as a separate species. - The globiferous and ophicephalous pedicellarise are 

 quite as those of chloroticus, the triphyllous ones I have not seen. Of Evech. australice Woods I 

 know nothing. 



A g a s s i z (Rev. of Ech. p. 502) thinks Evechinus to be closely allied to Tripncustes (Plipponoc] ; 

 that there is no nearer relation at all between these two genera is seen with all desirable distinctness 

 from the facts given above. The unpaired lateral tooth on the globiferous pedicellarise draws the 

 attention to Pseudechinus albocinctus', but the naked buccal membrane in the latter and the fact that 

 a primary tubercle is here found on all the ambulacral plates, do not indicate a very near relation 

 between the two forms. A quite similar form of globiferous pedicellarise is found in .Strongylocen- 

 trotusv tuberculatus and closely allied species, and these, no doubt, are its nearest relations. A more 

 thorough inquiring into this question must, however, be put off, until these species are treated. 



In Cat. rais. the species variolaris L,amk., paucituberculatus Blainv., and chloroticus Val. are 

 enumerated under the genus Heliocidaris. -- For the first of these species the older name of Stoino- 

 pneustes must be used; according to Agassiz (Rev. of Ech.) paitcituberculatus is synonymous with 

 this. As far as I can see, chloroticus must then be the type of the gemis Heliocidaris; the name of 

 Evechinus Verr. (1871) must then be dropped as being a much younger one, and I cannot but wonder, 

 why Agassiz, who otherwise takes great care to reestablish the oldest names, has here preferred the 

 name of Evechinus. 



To the genus Spharechimis Desor the species granularis (Lamk.), roseus Russo, australice A. Ag., 

 and piilcherrimus (Barn.) are referred; of these I have had no occasion to examine Sph. roseus, but 



